Nearby police stations located in the Seoul districts of Mapo and Seodaemun are usually compared to each other and, consequently, has developed a rivalry. The chief at the Mapo police station is Hwang Jae-Sung (Park Joong-Hoon), who is fearless when it comes to catching criminals & uses any means necessary. To top the Mapo station, the Seodaemun police station appoints its new leader Jung Wei-Chan (Lee Sun-Gyun). Jung Wei-Chan graduated from the prestigious police academy.